package cn.tedu.sp06.fallback;

import cn.tedu.web.util.JsonResult;
import org.springframework.cloud.netflix.zuul.filters.route.FallbackProvider;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.client.ClientHttpResponse;
import org.springframework.stereotype.Component;

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
@Component
public class ItemFB implements FallbackProvider {
    //针对那个服务应用当前降级
    //返回服务id
    //  item-service  只针对商品服务降级
    //   *-对所有服务降级
    //   null 对所有服务降级
    @Override
    public String getRoute() {
        return "item-service";
    }
    //返回的降级响应,封装在 response 对象中
    //根据自己应用的需求可以返回任意的响应数据
    //  - 错误提示
    //  - 缓存数据
    //  -执行业务运算,返回结果

    @Override
    public ClientHttpResponse fallbackResponse(String route, Throwable cause) {
        return new ClientHttpResponse(){

            @Override
            public HttpHeaders getHeaders() {
                HttpHeaders h = new HttpHeaders();
                h.add("Content-Type","application/json;charset=UTF-8");
                return h;
            }

            @Override
            public InputStream getBody() throws IOException {
                //JsonResult ---- {code:500,msg:系统服务故障,data:null}
                String json = JsonResult.err().code(500).msg("商品系统服务故障").toString();
                return new ByteArrayInputStream(json.getBytes("UTF-8"));
            }

            @Override
            public HttpStatus getStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR;  //500 internal error
            }

            @Override
            public int getRawStatusCode() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.value();   //500
            }

            @Override
            public String getStatusText() throws IOException {
                return HttpStatus.INTERNAL_SERVER_ERROR.getReasonPhrase();  //internal  error
            }

            @Override
            public void close() {
                //BAIS 流是内存数组的流,不占用底层系统的资源
                //不需要 close() 释放资源
            }
        };
    }


}
